---
id: CVE-2026-41182
aliases:
  - GHSA-rr7j-v2q5-chgv
  - PYSEC-2026-2583
title: 'LangSmith SDK: Streaming token events bypass output redaction'
summary: 'LangSmith SDK: Streaming token events bypass output redaction'
severity: medium
cvss: 5.3
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N'
vendor: langsmith
product: langsmith
ecosystem: npm
affected:
  - langsmith < 0.5.19
  - langsmith < 0.7.31
patched:
  - langsmith 0.5.19
  - langsmith 0.7.31
published: '2026-04-16'
updated: '2026-09-10'
sourceUpdated: '2026-09-10T03:51:03.075090864Z'
source: OSV
sourceUrl: 'https://osv.dev/vulnerability/GHSA-rr7j-v2q5-chgv'
references:
  - url: >-
      https://github.com/langchain-ai/langsmith-sdk/security/advisories/GHSA-rr7j-v2q5-chgv
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-41182'
  - url: 'https://github.com/langchain-ai/langsmith-sdk'
tags:
  - osv
  - npm
epss: 0.00358
epssPercentile: 0.2681
ingestedAt: '2026-07-13T18:58:02.925Z'
---

## Overview

## Summary

The LangSmith SDK's output redaction controls (hideOutputs in JS, hide_outputs in Python) do not apply to streaming token events. When an LLM run produces streaming output, each chunk is recorded as a new_token event containing the raw token value. These events bypass the redaction pipeline entirely — prepareRunCreateOrUpdateInputs (JS) and _hide_run_outputs (Python) only process the inputs and outputs fields on a run, never the events array. As a result, applications relying on output redaction to prevent sensitive LLM output from being stored in LangSmith will still leak the full streamed content via run events.

## Details

**Both JS and Python SDKs are affected.** The same pattern exists in both:

- **JS SDK**: `traceable.ts:997-1003` and `traceable.ts:1044-1050`
- **Python SDK**: `run_helpers.py:1924` and `run_helpers.py:1996`

In both SDKs, `new_token` events with raw `kwargs.token` values are added during streaming, and the redaction pipeline (`hideOutputs` in JS, `hide_outputs` in Python) only processes `inputs`/`outputs` — never `events`.

## Affected packages

- `langsmith < 0.5.19`
- `langsmith < 0.7.31`

## Remediation

Upgrade to a patched release:

- `langsmith 0.5.19`
- `langsmith 0.7.31`